Add another $15,000 to the tab that Brett Richards might owe his former employer.

The former general manager of the Ross Valley Sanitary District, who is in Marin County Jail facing charges of misappropriation of public funds, "improperly received salary payments in excess of his approved contract amount, from July 2010 through October 2010," according to a statement released by the district Wednesday. The alleged payments were flagged as part of a routine audit by the California Public Employees' Retirement System.

The release states, "The review found that Mr. Richards's salary in this period improperly included both a one-year retroactive Cost of Living Adjustment lump sum payment (for the period July 2009 to July 2010), and a subsequent COLA effective July 2010. There were no board approved changes to the general manager's salary in this period. The resulting combined excess salary payment was $15,718."

The district's current interim general manager, Greg Norby, said, "It's our understanding that it occurred at Richards' direction. It was not a clerical error or something like that."

Court records show that throughout 2010, Richards was involved in divorce proceedings with his wife Tiffani, who petitioned to dissolve the marriage. Records show that in April 2010 the court ordered a garnishment of Richards' wages to provide $3,250 per month in spousal support to his wife. The divorce became final in March 2011.

Richards, who was hired by the district in 2008, is accused of taking a $350,000 housing loan from the district that he never used for housing. He has been charged with nine felony counts including misappropriation of public funds, embezzlement and multiple counts of money laundering.

Marin County District Attorney Ed Berberian, who is prosecuting the case himself, said he had been notified of the salary overpayment, and it could result in criminal charges.

But Berberian said, "It's not part of this particular prosecution, and I'm not going to be addressing it directly in the evidence presentation at the preliminary hearing."

A preliminary hearing is scheduled in Marin Superior Court before Judge Terrence Boren at 9 a.m. Monday. Berberian said the hearing may need to be rescheduled, however, if another ongoing trial takes longer than expected.

Norby said the district will demand that Richards return the excess salary and intends to amend its civil lawsuit filed against Richards to include the $15,718 excess salary payment. The suit was filed last year seeking recovery of the home purchase loan. Norby said the district has also submitted a claim to its insurance carrier in hopes of recouping the loss.

Asked if the district's finance director or other district employees should have been aware of the salary overpayment and should have reported it to the board, Norby said, "That's a tough question. What this has shown is that the district was lacking in clear policies and standards for how the general manager's compensation changes were handled."

Norby said he is submitting policy revisions to the district's board for its review next month to remedy this situation. The new procedure would mandate two board member signatures and a separate finance manager signature to exercise any compensation rate changes for the general manager.

Board member Frank Egger, however, said he wants more detail about how the overpayment occurred.

"The board needs a full accounting of how this came about," Egger said. "We need to see the paper trail as to who authorized it, who paid it, who set the code for the payment. The board hasn't seen that."